Cosmetic products

ABSTRACT

The photo-destruction of an ingredient that is susceptible to photo-destruction in a stick cosmetic product can be retarded by controlling the ingress of air through the base of the dispenser of that product. The invention is particularly suitable for antiperspirant compositions containing palmatine disposed within a bottom-fill dispenser.

The present invention relates to cosmetic products particularly toanhydrous cosmetic products and more particularly to products forcontact application.

Cosmetic products for topical application to human skin comprise acosmetic composition housed within a dispenser. For many products, thechoice of dispenser is at the discretion of the producer of the product,and independent of the composition, provided that it satisfies genericconsiderations. Thus, for example, generally if the composition is inthe form of firm stick, for dispensing from a stick dispenser, thecomposition needs to satisfy the generic criteria that it remains solidand integral at both use and storage temperatures. Choices as to shapeof the dispenser and any mechanisms for dispensing the stick compositionwere made on the basis of the dispenser itself and did not take thecomposition into account. By the same token, when selecting ingredientsfor a stick composition, the selection has been made on the basis of theproperties of the ingredients themselves and their interaction withinthe composition without taking into account the dispenser from whichthey are dispensed.

However, it has now been found that in some circumstances, it isadvantageous to select the composition and the dispenser together, forexample in order to overcome or at least ameliorate the instability ofone or more ingredients in the composition. In particular, it has beenfound that the stability of certain ingredients in cosmetic formulationscan be improved by control of air ingress.

The cosmetics industry has either proposed or adopted several differentcontainers for cosmetic products ranging from a simple tub in which itscontents is typically dispensed by extraction of the contents on afinger, through to more complicated dispensers in which the contents isdispensed by an advancing platform/piston/elevator pushing a stickthrough an opposed opening, coupled with a threaded spindle advancingmechanism. Herein, the term “stick” dispenser indicates that thedispenser comprises both a platform and a screw-threaded advancemechanism. The simple tub is simple to seal, whereas the stick dispenseris much more difficult, and especially when the platform itselfcomprises one or more channels through which the dispenser can be filledthrough its base.

WO 2007029187 discloses compositions, including solid compositions,containing a material that the instant inventors have recognised to besusceptible to UV/photo-destruction during storage, but the text neitherrecognises that the material suffers from such susceptibility noridentifies a way to improve the storage stability of the compound incompositions containing it when dispensed from a stick dispenser.

WO20040219122 discloses polyol in silicone emulsion compositionscontaining many different ingredients, but does not specify materialsthat are susceptible to UV/photo-destruction, nor does it contemplateincorporation of such materials in a stick dispenser, but merely an airtight container with no explanation.

WO2005055964 discloses on page 21 an antiperspirant compositioncontaining an antiperspirant composition containing an encapsulatedfragrance disposed within an unspecified dispenser. There is nodisclosure of a material that is susceptible to UV/photo-destruction norany indication of the nature of the dispenser and accordingly providesno teaching as to whether any dispenser would or would not be capable ofimproving the storage stability of such a susceptible material.

WO20020699924 discloses anhydrous antiperspirant compositions, includingstick compositions on page 15, but does not contemplate expressly thepresence of materials that are susceptible to UV/photo-destruction. Thestick composition is contained in a conventional antiperspirant stickpackage. Accordingly, the disclosure does not provide any teaching tothe reader as to how to select a stick dispenser that would ameliorateor overcome the problem of impaired storage stability of materialssusceptible to UV/photo-destruction.

U.S. Pat. No. 4,232,977 discloses a dispenser for a stick compositionthat it alleges comprises a vapour tight seal (column 6, 3^(rd)paragraph). Unfortunately, it is the experience of Applicants that,notwithstanding the desirability of providing a seal that isvapour-tight, it is not possible in practice to do so when employingdispensers moulded from thermoplastics, and especially if the sealingsystem comprises but a single seal. The seal has to be loose enough topermit rotation of the shaft relative to the dispenser barrel, so thatthe sealing pressure of the seal is quite low so that several factorscontribute to impairing the seal, in practice rather than in theory.First, there is commonly some variation in the size of individualcomponents during the moulding operation and secondly, there can beimperfections in any seal at its periphery arising during the mouldingor possibly damage occurring after moulding during transportation beforeassembly. Thirdly, during assembly, there can be minor, localised damageto the seal as the shaft bearing the seal is inserted through anaperture in the base of the dispenser barrel. All of these factorscontribute to the concept of a vapour tight being theoretical. Moreoverthe disclosure in this specification does not contemplate anyrelationship between the extent to which a dispenser can seal at itsbase and it's applicability to compositions containing a material thatis susceptible to UV/photo-destruction.

The disclosure in U.S. Pat. No. 2,840,231 in regard to the seal issimilar to that of U.S. Pat. No. 4,232,977, and is similarly deficientin relation to the concept of the instant invention, namely selecting adispenser meeting a particular criterion in conjunction with theincorporation of an ingredient having a particular property.

The disclosure in EP0462925 relates to sealing a cap, rather than at thebase of a stick dispenser and does not contemplate any relationshipbetween the dispenser and UV/photo-sensitive ingredients.

EP0070257 discloses a sealing means comprising multiple flanges butthere is no disclosure of any relationship with an ingredient that issusceptible to UV/photo destruction and in particular no indication thatby appropriate selection of a stick dispenser, it is possible to affectthe storage stability of such an ingredient.

EP0189521 contemplates a dispenser lacking a screw-threaded advancemechanism and is silent concerning any relationship between thedispenser selection and an ingredient that is susceptible to UV/photodestruction.

The abstract of JP2005-281284 discloses compositions containingpalmatine, but provides no direction to the reader as to how to improveits stability during storage.

BRIEF SUMMARY OF THE PRESENT INVENTION

According to one aspect of the present invention, there is provided acosmetic product which is a composition disposed within a dispenser, inwhich the composition is in the form of a solid anhydrous stickcomposition containing one or more ingredients that are susceptible tophoto-destruction by visible/UV light and/or UV light and the dispensercomprises a barrel having opposed first and second ends, the first endbeing closed by a cap and the second end comprising a base, a platformintermediate between the first and second ends and screw-threaded meansfor advancing the platform towards the first end mounted on or adjacentto the second end, the composition being disposed between the platformand the first end of the barrel, in which the dispenser permits a %weight gain after 21 days in a test procedure as defined herein of notgreater than 150% of the % weight gain obtained in a referencedispenser.

By employing in conjunction such a composition and dispenser thatsatisfies the test, it is possible to at least ameliorate theinstability of one of more of such ingredients in such a stickcomposition. The prior art as summarised hereinbefore shows thatseparately one or more compositions containing such an ingredient mayhave been disclosed hitherto, and that one or more dispensers thatallegedly, but disputably, have been described that, if selected, mightbe suitable for the invention to be performed. However, separatedisclosure of elements of an invention does not direct the reader oruser to simultaneously make the two selections simultaneously, andparticularly does not direct the reader or user to make such selectionssimultaneously in order to improve the stability of that ingredient.

The invention is particularly relevant for the selection of combinationsin which the dispenser is bottom filled.

The relative weight gain is measured by the test procedure describedherein.

According to a second aspect of the present invention, there is provideda method for lengthening the period during which a compound that issusceptible to photo-destruction remains effective in a solidcomposition which comprises in a first stage identifying itssusceptibility to UV or photo-destruction, in a second stageincorporating it into a cosmetic composition, and thereafter introducingthe composition into a dispenser comprising a barrel having opposedfirst and second ends, the first end being closed by a cap and thesecond end comprising a base, a platform intermediate between the firstand second ends and screw-threaded means for advancing the platformtowards the first end mounted on or adjacent to the second end, inbetween the platform and the first end of the barrel, in which thedispenser permits a % weight gain after 21 days in the test procedure asdefined herein of not greater than 150% of the % weight gain obtained inthe reference dispenser.

In a third aspect of the present invention there is provided a cosmeticproduct according to the first aspect that is an antiperspirant ordeodorant product in which the cosmetic active comprises anantiperspirant or deodorant active.

A MORE DETAILED DESCRIPTION OF THE INVENTION, INCLUDING PREFERREDEMBODIMENTS

The present invention is concerned with stick products displayingimproved stability during exposure to ambient air, in visible and UVlight, and is especially applicable where the air is humid. Suchconditions are prevalent in various rooms of most houses in whichcosmetic products are commonly stored, such as in or adjacent to abathroom or shower-room or in the vicinity of wash hand basins, forexample in order to facilitate bodily application of such productsshortly after cleansing. Where the cosmetic composition contains anactive ingredient that suffers from photo-destruction, the effectivenessof that ingredient is progressively impaired with the passage of timeunless measures are taken to retard, ideally to zero, the rate at whichthe ingredient is destroyed.

The instant invention is of particular applicability to counterdegradation of ingredients which is caused or accelerated by water, suchas is present in humid air.

The present invention is of relevance to a cosmetic composition whichcontains an ingredient that is affected adversely by storage of such aproduct until it is consumed, which can commonly last for up to severalmonths. Visible and UV light herein is considered to comprise lighthaving a wavelength of from 290 to 740 nm and particularly up to 700 nm.Accordingly, the invention is especially applicable in regard toproducts that may be exposed to sunlight, since it comprises lightacross the full spectrum from 290 to 740 nm and particularly up to 700nm, albeit possibly of reduced intensity across a fraction of thespectrum where that sunlight has passed through glass, such as through aglass window.

The invention broadly contemplates two mechanisms in which visible/UVlight such as particularly sunlight can cause destruction of compounds.One mechanism comprises direct absorption of light by the compound inquestion, leading to its excitation and reaction in that excited state.Without being restrictive, many destructive reactions can be classifiedas one or other of hydrogen abstraction, internal rearrangement orelectron transfer reactions. Of these reactions, the most common is theclassification of electron transfer. A second mechanism can beclassified as sensitized destruction which proceeds as in the firstmechanism by a compound being promoted to an excited state by absorptionof light, but thereafter, the excited state is transformed into areactive intermediate which reacts with a complementary compound.Although not restricted to the creation of such reactive intermediates,the two most commonly formed intermediates are free radicals and singletoxygen.

Many substances considered susceptible to photo-destruction canalternatively be classified as Photolabile, by which is meant asubstance which when dissolved in a solvent and exposed to simulatedFlorida sunlight degrades by more than 50 mol %.

The solvent may be selected from: water at pH 4-8, ethanol, methanol,acetonitrile, nonane, toluene, glycerol, or combinations thereof. Thesubstance at the start of the test should have a maximum optical densitybetween 290 and 700 or 740 nm, at a path length of 1 cm, of 0.5-1. Thetest should be carried out with a 1 cm light path length.

The dissolved substance should be exposed to 13860 kJ/m² in the range300-800 nm of simulated Florida sunlight produced by a Xenon arc lamp ina “weatherometer”. A suitable weatherometer for such tests is an AtlasCi3000+ Weatherometer.

Degradation of the substance may be monitored by UV-VIS spectroscopy orby chromatographic extraction and quantification of the substance.

(1) Molecules which produce singlet oxygen under exposure to light inthe range 290-700 or 740 nm and oxygen with a quantum yield greater than0.05 in an organic solvent (methanol, acetonitrile, benzene, toluene,dimethylformide, CCl₄) or D₂O.

Quantum yields for photosensitized formation of singlet oxygen may befound in J. Phys. Chem. Ref. Data 1993, vol 22, nol pp 113-262.

Examples of such substances include chlorophyll, coumarin, porphyrins,porphins, myoglobin, riboflavin, bilirubin, and methylene blue, xanthenebased dyes.

(2) Molecules comprising aromatic heterocycles, and particularly whenthe heteroatom is charged. Desirable examples include palmatine ormalvidin chloride. Other counter-ions can be employed if desired.

(3) Phenols which lack a tertiary butyl group that would serve tostabilise the phenol, adjacent to the OH group. The phenols arepreferably polyphenols, such as catechin epicatechin, epicatechingallate, epigallocatechin gallate resorcinol, gallic acid, isolquiritin

(4) biological molecules: Vitamins, such as vitamin C, vitamin B3 and/orderivatives thereof, Co-enzymes, Enzymes and proteins

(5) Unsaturated aliphatic olefinically unsaturated fatty carboxylicacids comprising a C—H bond alpha to the olefinic unsaturation;

Such compounds are contemplated for incorporation into cosmetic productson account of their beneficial properties. Thus, for example, various ofthem, such as dyes, can colour the composition rendering it attractiveto a consumer.

Others such as C18 unsaturated carboxylic acids, can combat irritationon skin induced by co-ingredients. Yet others, such as vitamins, can actas antioxidants and thereby protect the skin from harmful externalchallenges. Still others can improve or disguise the appearance of hairon skin, such as by retarding its growth, either shorter and/or finer.

It is particularly desirable in some embodiments to employ a substancein accordance with class (1). In other embodiments, it is of benefit toemploy a substance in accordance with class (2). In still otherembodiments, it is desirable to employ a substance in accordance withclass (3).

If desired, a mixture of two or more such substances from classes (1) to(5) can be employed together, selected from within a class or fromdifferent classes.

In relation to antiperspirant or deodorant products, it is particularlydesirable to employ compounds, such as those in the classes mentionedabove, that improve skin condition or counter skin aging or combatirritation, or act as antioxidants or retard hair growth.

An ingredient is considered to be adversely affected if the rate ofimpairment of a desired property is accelerated or the extent ofimpairment increased by storage in daylight in ambient air compared withstorage in the dark in air of zero percent relative humidity. Many suchingredients are expressly recognised from their data sheets to besusceptible to photo-destruction, by reference to their extinctioncoefficient having a peak value within the visible/UV light spectrum ofat least 100 mol⁻¹cm⁻¹, particularly at least 500 mol⁻¹cm⁻¹ andespecially at least 1000 mol⁻¹cm⁻¹. For the others, their susceptibilitycan be assessed as indicated above, or indeed their extinctioncoefficient can be measured using a conventional test employing astandard cell such as of 1 cm width and a solution of the compound in acompatible solvent at a known concentration through which light isshone, and the net extent of absorption measured across the spectrum(after allowance for the solvent alone).

It will be understood that, herein, the “peak value” is the highestvalue for the extinction coefficient within the spectrum of from 290 nmto 740 nm. In the event that the value for the extinction coefficientcontinues to increase through the boundary of said spectrum, then thewavelength for the peak is taken to be at the spectrum boundary itself,that is to say 290 nm or 740 nm as the case may be.

It will further be recognised that certain, but not all, ingredientsindicated above which are potentially susceptible to photo-destructioncontain a chromophore.

The concentration of the ingredient susceptible to photo-destruction isnormally at least 0.0001% w/w of the composition, in many embodiments atleast 0.0005% w/w and in some preferred embodiments, at least 0.001%.Said ingredient is commonly present at a concentration not exceeding 10%w/w, and often not higher than 5% w/w of the composition. In a number ofhighly desirable compositions, for example those containing asusceptible ingredient affording skin care or hair minimisation benefit,the ingredient is present at a concentration of up to 1% w/w.

For the avoidance of doubt, an astringent antiperspirant active, such assalts described hereinafter, is considered not to be an ingredientaffected adversely by such storage.

Products herein comprise an anhydrous composition, by which is meantthat the composition is free from detectable free water. Free waterexcludes water of hydration.

The dispenser for the stick material preferably demonstrates a weightincrease after 21 days in the test procedure of not greater than 125%and particularly not greater that 110% of the weight gain in the primaryreference dispenser, and especially at or less than in the primaryreference dispenser.

Test Procedure for Assessing Suitability of a Dispenser.

Herein, in the test procedure, the reference and the trial dispensersare each filled with approximately a 50 g sample of the stickcomposition specified hereinbelow, with the stick “former” removed ifthe dispenser has been bottom filled, and a close-fitting cap is fittedover the open end. Bottom filling, as is conventional, means that thestick composition is filled into the dispenser through an aperture atthe base of the dispenser and through one or more passages in theplatform, the composition being retained in the dispenser barrel betweenthe platform and the first end of the barrel. In respect of dispensersemploying a screw-threaded mechanism for advancing the platform,dispensers which include the reference dispenser, the mechanism forplatform advancement is mounted on the barrel, and any seal fitting inor covering a filling aperture. The sample and reference dispenser arefilled such that the stick material occupies the entire volume betweenthe platform and the open end of the barrel.

The filled sample and reference dispensers are weighed and then stoodupright side by side in a humid domed chamber having a diameter of 30 cmand a height of 25 cm which contains a bowl of deionised water whichhumidifies the air within the chamber to greater than 90% RH at 23° C.,and stored in a room at laboratory ambient temperature, the roomtypically reaching about 22-23° C. during the day, but often falling tobelow 20° C. overnight. The test procedure measures the relative weightgain of the products containing the same reference compositionidentified below to identify the relative effectiveness of the dispenserat controlling air ingress. Although variation in the absolute rate ofweight gain may occur as a result of for example fluctuation in thetemperature, any variation in the relative humidity within the chamberremains within the range of at least 90% RH, and any such absolutevariations apply to both sample and reference products simultaneously,the comparison using the same defined composition, so that the relativeweight gain is not affected.

At intervals, preferably weekly, the dispensers are weighed and replacedin the chamber, the difference in weight being measured. For the purposeof determining whether or not the sample dispenser is in accordance withthe present invention, the weight increase comparison is made after 21days, namely on the 22^(nd) day of the test. The weighing on the 22^(nd)day should take place at substantially the same time of day as theinitial weighing. Preferably, the data is collected on at least 5dispensers for each of the reference and sample dispensers, andaveraged. Preferably, the trial is conducted using dispensers that havenot been filled previously. Primary reference dispensers expressly andsolely for the purpose of conducting the test procedure, and in numberssufficient for that purpose, are held by and available from UnileverResearch & Development, Quarry Road East, Bebington, CH63 3JW, England,at the cost of the requester. Any such request for reference dispensersshall be marked “Kenzo Reference Dispenser, 1.6 oz Dove White Meteor”.

The test preferably employs the same weight, about 45 g of the referencestick material in each dispenser. The reference dispenser is a nominal1.6 oz dispenser that accommodates about 45 g material. As is describedin more detail hereinafter, the reference dispenser is bottom filledthrough a central opening within the rotor wheel mounted through acentral aperture in the base of the dispenser barrel and thence thoughpassageways in the platform. The platform is skeletal. The dispensercomprises essentially two orthogonal seals sealing the rotor wheel intothe aperture at the base of the barrel.

For comparison with markedly different weights of stick material in thereference and test dispensers, the average weight gain should beconverted to an average gain per 100 g of stick material.

Such reference dispensers constitute the primary reference dispenser.If, as may happen eventually, a supply of the primary referencedispenser is exhausted, then a secondary reference dispenser can besupplied instead, namely one that has been referenced to the primaryreference dispenser, together with the conversion factor to determinewhether or not the invention test is met. Thus, if the secondaryreference dispenser permits a weight increase that is “x” times theweight increase of the primary reference dispenser, then the appropriateceiling ratio to determine whether or not a sample dispenser satisfiesthe instant invention is 1.5/x . Such conversion factor shall besupplied together with the secondary reference dispenser.

The stick composition for conducting the above assessment of thesuitability of a dispenser is as follows:—

Chemical Name Trade name Supplier % w/w Cyclopentasiloxane DC245 Dow27.00 Corning PPG-14 Butyl Ether Fluid AP Amerchol 9.50Butylhydroxyltoluene BHT, 100% Active Eastman 0.05 Dimethicone DC200/50cst Dow 1.00 Corning C₁₂₋₁₅ Alkyl Benzoate Finsolv TN Finetex 15.00Steareth-100 Brij 700 Uniqema 0.50 Stearyl Alcohol Lanette C18 DeoCognis 18.00 Hydrogenated Castor Castor Wax MP-80 Caschem 3.50 oilPolyethylene wax Performalene 400 1.00 PEG-8 Polyethylene Fluka 2.00glycol 400 Fumed silica Aerosil 200 Degussa 0.75 Aluminium AACH- A418Summit 20.00 Chlorohydrate Sunflower Oil Agripure 80 Cargill BV 0.50Fragrance 1.20

The product according to the present invention comprises at least onecosmetic active ingredient, for example one or more that can impartcolour, such as a pigment, inhibit body odour generation, inhibitperspiration, impart moisturisation, combat ageing of skin, conditionskin or hair, protect skin against exposure to sunshine and/orameliorate sunburn or repel insects.

The invention product especially convenient comprises an antiperspirantor deodorant active.

Antiperspirant actives for use herein are often selected from astringentactive salts, including in particular astringent aluminium, zirconiumand mixed aluminium/zirconium salts, including both inorganic salts,salts with organic anions and complexes. Preferred astringent saltsinclude aluminium, zirconium and aluminium/zirconium halohydrate salts,and especially chlorohydrates. Aluminium/zirconium chlorohydratescomplexed with glycine are particularly desirable antiperspirant activesin stick compositions herein.

Aluminium halohydrates are usually defined by the general formulaAl₂(OH)_(x)Q_(y).wH₂O in which Q represents chlorine, bromine or iodine,x is variable from 2 to 5 and x+y=6 while wH₂O represents a variableamount of hydration. Aluminium chlorohydrates comprise a mixture ofpolymeric species, for example species containing respectively 12, 24 or36 aluminium atoms and the relative ratio of the various species iscontrolled by the manufacture process. It is desirable to include a highproportion of Al 24 species, such as products obtained following theteaching in EP-A-6739, sometimes called activated aluminiumchlorohydrates.

Zirconium actives can usually be represented by the empirical generalformula: ZrO(OH)_(2n-nz)B_(z).wH₂O in which z is a variable in the rangeof from 0.9 to 2.0 so that the value 2n-nz is zero or positive, n is thevalency of B, and B is selected from the group consisting of chloride,other halide, sulphamate, sulphate and mixtures thereof. Possiblehydration to a variable extent is represented by wH₂O. Preferable isthat B represents chloride and the variable z lies in the range from 1.5to 1.87. In practice, such zirconium salts are usually not employed bythemselves, but as a component of a combined aluminium andzirconium-based antiperspirant.

The above aluminium and zirconium salts may have coordinated and/orbound water in various quantities and/or may be present as polymericspecies, mixtures or complexes. In particular, zirconium hydroxy saltsoften represent a range of salts having various amounts of the hydroxygroup. Zirconium aluminium chlorohydrates may be particularly preferred.

Antiperspirant complexes based on the above-mentioned astringentaluminium and/or zirconium salts can be employed. The complex oftenemploys a compound with a carboxylate group, and advantageously this isan amino acid. Examples of suitable amino acids include dl-tryptophan,dl-β-phenylalanine, dl-valine, dl-methionine and β-alanine, andpreferably glycine which has the formula CH₂(NH₂)COOH. It is highlydesirable to employ glycine complexes of a combination of aluminiumhalohydrates and zirconium chlorohydrates together with amino acids suchas glycine.

Many suitable antiperspirant salts have an Al/Zr ratio in a range from 2to 10, especially 2 to 6, a metal to Cl ratio from 2.1 to 0.9:1 and avariable amount of glycine. In some highly desirable complexes, themetal:Cl ratio is from 0.9:1 to 1.25:1 and in others it is from 1.3:1 to1.45:1.

Other actives which may be utilised include astringent titanium salts,for example those described in GB 2299506A.

The proportion of solid antiperspirant salt in a suspension compositionnormally includes the weight of any water of hydration and anycomplexing agent that may also be present in the solid active.

The antiperspirant salt in an anhydrous stick composition isparticulate, commonly having particles mainly with a diameter within therange of 0.1 to 200 μm, such as providing a mean particle size in therange of from 3 to 20 μm.

The particulate antiperspirant active may be present in the form ofhollow spheres or/and non-hollow particles at the discretion of themanufacturer of the invention antiperspirant product. Non-hollowparticles can be made, if desired, by crushing hollow particles. Whereit is desired that the composition is translucent in bulk or to reducethe appearance of visible deposits on the skin to which the compositionis applied or on clothing which comes into contact with the composition,it is preferable for the antiperspirant particles to be substantiallyfree from hollows, such as greater than 90% by weight of the particlesand especially greater than 95% by weight.

The antiperspirant active is often present at a concentration of from0.1 to 35% by weight of a stick composition, particularly at least 5% byweight and in many very desirable compositions at least 15% by weight.Often, its concentration is not greater than 30% by weight, and in manyeffective compositions is up to 26% by weight. At low concentrationssuch as up to 5% by weight, the active is more noticeable as adeodorant, whereas at the higher concentrations and especially at above10% concentration, it increasingly demonstrates effectiveness to reduceperspiration whilst retaining its ability to inhibit malodour formation.

Suitable deodorant actives can comprise deodorant effectiveconcentrations of antiperspirant metal salts, deoperfumes, and/ormicrobicides, including particularly bactericides, such as chlorinatedaromatics, including biguanide derivatives, of which triclosan (egIrgasan DP300 or Triclorban), and chlorhexidine warrant specificmention. Another class of effective deodorants comprises polyaminopropylbiguanide salts such as are available under the trade mark Cosmosil.Such materials commonly act as bactericides. A still further class ofmaterials that can inhibit malodour formation comprise chelators thatcan sequester iron, and thereby retard bacterial growth, includingaminopolycarboxylates such as EDTA or higher homologues such as DTPA.Deodorant actives other than astringent metal antiperspirant salts arecommonly employed at a concentration of from 0.1 to 5% by weight, andparticularly 0.1 to 2% by weight.

Compositions herein commonly comprise one or more carrier liquids, whichare water-immiscible and thus sometimes are referred to as oils. Theliquids often constitute from 30 to 90% by weight of the composition andin many desirable compositions at least 40% and particularly at least50% by weight. Their total weight proportion is often not greater than80% and in many practical embodiments of the invention is up to 70%.

The carrier liquids often include silicone oils, which may be volatileor non volatile or a mixture of both and commonly also or alternativelycomprise non-silicone oils.

It is preferred that the hydrophobic carrier liquids include a volatileliquid silicone, i.e. liquid polyorganosiloxane. To class as “volatile”such material should have a measurable vapour pressure at 20 or 25° C.Typically the vapour pressure of a volatile silicone lies in a rangefrom 1 or 10 Pa to 2 kPa at 25° C.

It is desirable to include a volatile silicone because it can give a“drier” feel to the applied film after the composition is applied toskin, for example constituting at least 25% and particularly at least40% by weight of the carrier liquids.

Volatile polyorganosiloxanes can be linear or cyclic or mixturesthereof. Preferred cyclic siloxanes include polydimethylsiloxanes andparticularly those containing from 3 to 9 silicon atoms and preferablynot more than 7 silicon atoms and most preferably from 4 to 6 siliconatoms, otherwise often referred to as cyclomethicones. Preferred linearsiloxanes include polydimethylsiloxanes containing from 3 to 9 siliconatoms. The volatile siloxanes normally by themselves exhibit viscositiesof below 10⁻⁵ m²/sec (10 centistokes), and particularly above 10⁻⁷m²/sec (0.1 centistokes), the linear siloxanes normally exhibiting aviscosity of below 5×10⁻⁶ m²/sec (5 centistokes). The volatile siliconescan also comprise branched linear or cyclic siloxanes such as theaforementioned linear or cyclic siloxanes substituted by one or morependant -0-Si(CH₃)₃ groups. Examples of commercially available siliconeoils include oils having grade designations 344, 345, 244, 245 and 246from Dow Corning Corporation; Silicone 7207™ and Silicone 7158™ fromUnion Carbide Corporation; and SF1202™ from General Electric.

The hydrophobic carrier employed in compositions herein canalternatively or additionally comprise non-volatile silicone oils, whichinclude polyalkyl siloxanes, polyalkylaryl siloxanes andpolyethersiloxane copolymers. These can suitably be selected fromdimethicone and dimethicone copolyols. Commercially availablenon-volatile silicone oils include products available under thetrademarks Dow Corning 556 and Dow Corning 200 series. Other nonvolatile silicone oils include that bearing the trademark DC704.Incorporation of at least some non-volatile silicone oil having a highrefractive index such as of above 1.5, for example in a proportion of atleast 10% by weight of the silicone oils can be beneficial in somecompositions.

Silicone oils may be supplemented, if desired, by other oils, and insuch instances, there is preferably, sufficient liquid silicone toprovide at least 10%, better at least 15%, by weight of the wholecomposition.

Silicon-free hydrophobic liquids can be used, preferably in addition toliquid silicones. Silicon-free hydrophobic organic liquids which can beincorporated include liquid aliphatic hydrocarbons such as mineral oilsor hydrogenated polyisobutene, often selected to exhibit a lowviscosity. Further examples of liquid hydrocarbons are polydecene andparaffins and isoparaffins of at least 10 carbon atoms. Hydrocarbonliquids preferably are present in a range of from 0 to 20% w/w andespecially from 0 to 5% of the oils.

Other suitable hydrophobic carriers comprise liquid aliphatic oraromatic esters. Suitable aliphatic esters contain at least one longchain alkyl group, such as esters derived from C₁ to C₂₀ alkanolsesterified with a CB to C₂₂ alkanoic acid or C₆ to C₁₀ alkanedioic acid.The alkanol and acid moieties or mixtures thereof are preferablyselected such that they each have a melting point of below 20° C. Theseesters include isopropyl myristate, lauryl myristate, isopropylpalmitate, diisopropyl sebacate and diisopropyl adipate.

Suitable liquid aromatic esters, preferably having a melting point ofbelow 20° C., include fatty alkyl benzoates. Examples of such estersinclude suitable C₈ to C₁₈ alkyl benzoates or mixtures thereof,including in particular C₁₂ to C₁₅ alkyl benzoates eg those availableunder the trademark Finsolv.

Ester oils, be they aliphatic or aromatic desirably comprise from 0 to50% w/w, eg 5 to 40% w/w of the oils.

Yet other suitable ester oils, which desirably provide up to 10% w/w ofthe carrier liquids or alternatively from 1 to 6% w/w of the compositioncomprise triglyceride oils, such as those extractable from plantsderivable from unsaturated carboxylic acids, such as C16, C18 and/orC20. Suitable examples of such triglyceride oils include caster oil,borage oil, coriander seed oil, safflower oil and sunflower seed oil.

Further instances of suitable hydrophobic carriers comprise liquidaliphatic ethers derived from at least one fatty alcohol, such asmyristyl ether derivatives e.g. PPG-3 myristyl ether or lower alkylethers of polygylcols such as an ether having named as PPG-14 butylether by the CTFA. Such ethers desirably constitute from 0 to 20, andpreferably from 0 to 10% w/w of the oils.

Yet other oils which can beneficially be included comprise hydrophobicaliphatic alcohols which are liquid at 20° C. and have a boiling pointof above 100°. Such oils are preferably employed in a proportion of from0 to 50% w/w of the carrier liquids, and are of especial benefit for usein conjunction with amido gellants, when they are preferably employedwithin the proportion of from 25 to 50% w/w of the carrier oils.Especially desirable hydrophobic aliphatic alcohols are branched chainalcohols of at least 15 carbon atoms up to 30 and especially up to 25,including isostearyl alcohol, hexyl-decanol octyl-dodecanol anddecyl-tetradecanol. Other suitable water-immiscible alcohols includeintermediate chain length linear alcohols, commonly containing from 9 to13 carbon atoms, such as decanol or dodecanol. A further suitablealcohol is benzyl alcohol.

Stick compositions herein normally comprise a structurant or gellant forthe carrier liquid.

One class of structurant which is desirable by virtue of its longstanding proven capability to produce firm solids (sticks) compriseswaxes. Herein, the term wax is employed to encompass not only materialsof natural origin that are solid with a waxy feel and water-insoluble at30-40° C., but melt at a somewhat higher temperature, typically between60 and 95° C., such as beeswax, candelilla or carnauba wax and theirsynthetic derivatives or analogues for example those available fromKoster Keunen under the marks K62, K67, or K82, but also materialshaving similar waxy properties. Such other waxes include hydrocarbonwaxes, eg paraffin wax, mineral wax and microcrystalline wax; syntheticwaxes, such as polyethylene waxes of 300 to 600 daltons; waxyderivatives or waxy components of natural waxes, such as estercomponents, either extracted or synthesised, solid ester derivatives ofglycerol or glycol, typically with linear saturated fatty acids, usuallycontaining a significant fraction of C₁₆₋₂₂ acid residues, which may besynthesised or obtained by hydrogenating the corresponding natural oil,such as caster wax; petroleum waxes, waxy silicone polymers containingalkyl substituents of at least C₁₀ chain length; and, importantly, waxyfatty alcohols, that normally are linear and often contain from 14 to 24carbons, such as stearyl alcohol, cetyl alcohol and/or behenyl alcohol.

Waxes are commonly employed at an amount of at least 12% by weight ofthe carrier oils, such as in the range of from 15 to 40% w/w and in manyinstances from 20 to 35% w/w. When considering the entire composition,the wax or mixture of waxes often constitute from 12 to 24% w/w of thecomposition, and in many compositions from 14 to 20% w/w.

A second class of structurants comprises oil-soluble copolymers ofstyrene and a short chain alkylene diene like butadiene, sometimesreferred to as SEBS copolymers, obtainable under the trade mark Kraton.Other suitable polymeric structurants include copolymers of silicone andpolyamides. Polymeric structurants in this second class can typically beemployed at a concentration of from 3 to 12% w/w of the carrier oilblend.

A third class of structurant comprises non-polymeric materials that forma network of fibres within an oil phase, it is surmised by individualmolecules or pairs of molecules stacking one above the other in anordered fashion. One example is hydroxystearic acid. Many of suchstructurants comprise amide or ester links within the molecule. Examplesof such structurants containing ester groups include α cellobioseoctanonanoate and related compounds, and β maltose octatetradecanoate.Other materials include, in combination β sitosterol and γ oryzinol.Other examples include (S,S)-1,4-Di-O-Benzyl-D-Threitol and relatedcompounds, such as disclosed in U.S. Pat. No. 6,410,001. Examples ofdesirable amide-containing fibre-forming structurants include 1,2- or1,3-bisalkylamido cyclohexanes as described in U.S. Pat. No. 6,410,003,hydroxystearic acid amides described in U.S. Pat. No. 5,840,286,alkylamide derivatives of succinic or citric acid described in U.S. Pat.No. 6,190,673, aspartame-based cyclodipeptides having aromatic orcycloaliphatic substitution, eg the thymol derivative, as described inEP 1465586, and N-acyl aminoacid dialkylamides such as N-LauroylglutamicAcid Di-N-Butylamide and N-(2-ethyl-hexyloyl)glutamic AcidDi-N-Butylamide and related compounds described in respectively U.S.Pat. No. 3,696,9087 and US2002/0159961. Structurants in this third classtend to be able to form gels at comparatively low concentrations, andparticularly those comprising amide links. They are commonlycontemplated in a w/w amount of from 1 to 20% of the oil blend, and inmany favourable compositions from 3 to 10% of the oil blend. Expressedin terms of the entire composition, the amount of such structurants isoften from 3 to 7% w/w of the composition.

Solid compositions herein can comprise, if desired, one or morehumectants, preferably comprising at least 2 hydroxyl substituents.Preferred humectants comprise glycerol and PEG (polyethylene glycol)having an average molecular weight of from 200 to 620. Such a humectantcan desirably be employed at a concentration of at least 0.25% w/w andparticularly at least 0.5% w/w of the composition. The humectant ispreferably present at a concentration of up to 10% w/w, in manyinstances up to 8% w/w, and often advantageously from 1 to 4% w/w of thecomposition.

The humectant can advantageously be incorporated in the stickcompositions herein together with a triglyceride oil, particularlyderived from unsaturated C₁₋₈ aliphatic acids. The weight ratio of thesetwo constituents is desirably in the range of from 4:1 to 1:4, forexample providing a combined weight of from 1.5 to 6% w/w of thecomposition.

The solid compositions herein can if desired comprise one or more minoringredients that can be contemplated in cosmetic compositions. Suchingredients normally comprise in total not more than 10% by weight ofthe composition. Such optional constituents can comprise sensorymodifiers, such as talc or finely divided polyethylene, such as in anamount of up to 5% by weight; fragrance, including, if desireddeoperfumes, often in an amount of up to 4%, eg 0.3 to 2% by weight,colorants; skin cooling agents such as menthol; wash-off agents such asnon-ionic surfactants.

The solid cosmetic compositions contemplated herein and containing aningredient that is susceptible to photo-degradation can be made bymethods hitherto contemplated for similar compositions from which thephotodegradable ingredient is absent.

By way of example, in the context of making an antiperspirantcomposition, hitherto described methods can be followed. In one suchmethod, a blend of oils is formed and heated to a temperature which ishigh enough to dissolve the structurant therein. This temperature iscommonly in the range of from 70 to 95° C. when employing a wax, andcommonly in the range of 70 to 140° C. when employing a polymer orfibre-forming structurant (classes 2 and 3, supra). The precisetemperature to be attained depends on the structurant itself. Thecomposition is often allowed to cool to a temperature below thestructurant dissolution temperature, but above the compositionsolidification temperature and the antiperspirant and thephoto-degradable ingredient and other and optional ingredientsintroduced with agitation to prevent settling. The fragrance is oftenthe last material to be introduced. The resultant mixture is introducedinto the dispenser whilst it is still mobile, for example at atemperature of at least 3° C. above its normal solidificationtemperature if filling takes place under gravity, or within +/−2° C. ofthat temperature if it is injected under external pressure.

It is however at the discretion of the producer to introduce some or allof the ingredients into the oil blend before it is heated to structurantdissolution temperature. Likewise, it is an alternative to introducesome or all of the structurant in a proportion of the oil blend that isheated to dissolve the structurant and other ingredients together withthe remainder of the oil blend having a lower temperature, and the twofractions brought together to form a mixture.

The dispenser for the invention product can be selected in accordancewith the test procedure identified above. The primary referencedispenser itself is a particularly suitable dispenser for the presentinvention, because it controls extremely well the inflow of ambient airinto its interior through its base. Ambient air, as mentionedhereinbefore, will be particularly humid in locations such as bath orshower rooms or adjacent to washing facilities. However, in tropical orsub-tropical climes, the air is naturally humid, often exceedingrelative humidity of 70%. Even humidities prevalent in temperateclimates such as 40 to 50% can be considered moist. The top of solidcosmetic dispensers are commonly equipped with their tightly fittingcap, often a friction fit, but the base of dispensers can offer apassage for air ingress, for example between the base itself and themounting for the rotor. In the primary reference dispenser sealing isespecially effective, by virtue of employing a combination of sealingsurfaces and seals, orthogonal to each other. The use of twin sealsoffers a recognisable gain over use of a single seal, providing twolocations where inflow is obstructed, but the benefit is compounded byemploying them orthogonally. Dispenser bodies and rotors are commonlyproduced by mass production methods, moulding them from thermoplastic.Some minor variations between individual bodies and rotors isaccordingly inevitable, so that the sealing system has to encounterslightly different spacings between the opposed surfaces of dispenserbase and the rotor mounting that are bridged by the seals. Moreover, inuse, rotation of the rotor will flex the various elements of thedispenser, exacerbating any gaps. Orthogonality of the seals inevitablyrequires the seals to be bridging two sets of opposed surfaces, the oneset being orthogonal to the other. Thus, the risk is reduced of minorvariations in manufacture and flexing in use resulting in greater airingress.

Advantageously, the reference dispenser, and particularly if it is abottom-filled dispenser, employs for at least one of its seals, a clawseal. This is an especially effective seal for preventing air ingress,by virtue of its tip flexibility.

The test procedure identified herein is particularly suitable foridentifying and selecting those bottom-fill stick dispensers which arepreferable for incorporating compositions containing an ingredient thatis sensitive to photo-degradation. In such dispensers, there is asignificant surface area of stick material that is exposed at the baseof the platform and thus in contact with air that can ingress throughthe base of the dispenser. In particular, the test procedure canidentify suitable dispensers in which the area of exposed passage at thelower side of the platform constitutes at least 30%, often at least 50%and particularly at least 60% of the transverse surface area of thedispenser barrel within which the platform fits, such as up to 90% ofthe transverse surface area, and in many practical embodiments up to 85%of the transverse surface area. In calculation the %, the centralthreaded interior aperture of the hub of the platform is excluded.

Having summarised the present invention and provided general orpreferred embodiments, specific embodiments will now be described morefully by way of example only.

In these Examples, the composition summarised below was made by thefollowing general method:

A blend of the oils formed with stirring in a pot was slowly heated to atemperature in the region of 80 to 85° C. The solid structurants wereintroduced slowly with stirring until by eye the structurants were notvisible as a separate dispersed phase. The mixture was allowed to coolto between 70 and 75° C. and the particulate antiperspirant and othermaterials were introduced, including an ingredient containing palmatinewhich is susceptible to photo-degradation, the mixture being stirred toprevent sedimentation. The final ingredient added was the fragrance. Thesuspension of particulates in an oil phase was allowed to cool furtheruntil it was between 5 and 10° C. above its normal solidificationtemperature and thereafter poured into the chosen dispenser through acentral aperture in its base, be it a dispenser satisfying the criterionidentified herein or a comparison dispenser that does not satisfy thecriterion. The resultant products were inverted after the compositionhad solidified and allowed to cool to laboratory ambient. The centralaperture was plugged and the dispenser subsequently subjected to testingto determine the stability of the photo-sensitive ingredient.

Chemical Name Trade name Supplier % w/w Cyclopentasiloxane DC245 DowCorning 26.0975 PPG-14 Butyl Ether Fluid AP Amerchol 9.50Butylhydroxyltoluene BHT, 100% Active Eastman 0.05 Dimethicone DC200/50cst Dow Corning 1.00 C₁₂₋₁₅ Alkyl Benzoate Finsolv TN Finetex 15.00Steareth-100 Brij 700 Uniqema 0.50 Stearyl Alcohol Lanette C18 DeoCognis 17.40 Hydrogenated Castor Castor Wax MP-80 Caschem 3.50 oilPolyethylene wax Performalene 400 1.00 PEG-8 Polyethylene glycol Fluka2.00 400 Fumed silica Aerosil 200 Degussa 0.75 Aluminium AACH- A418Summit 20.00 Chlorohydrate Sunflower Oil Agripure 80 Cargill BV 0.50Palmatine Depiline 2XC (0.16% Sederma 1.50 active) Aluminium salt ofUnipure LC324 Sensient 0.0025 monoazoic dye Fragrance 1.20

Palmatine has an extinction coefficient that is highest of about2700/Mcm at 280 nm, so that for the purpose of this invention, the“peak” extinction coefficient is taken to be at 290 nm.

The primary reference dispenser is described herein with reference tothe accompanying figures in which

FIG. 1 represents a cross section through the dispenser, viewed alongits minor transverse axis;

FIG. 2 represents a cross section through the dispenser, viewed alongits major transverse axis.

The dispenser comprised barrel (1) of oval cross section having atubular axially extending sidewall (2) with an open upper end (3) inwhich is fitted a stick former (4) and which is covered by a cap (5)that friction fits onto the sidewall (2) and is held by a pair of shortribs and grooves (6), (7). Sidewall (2) has a base wall (8) having acentral circular axial wall (9) joined to an annular lateral wallsection (10). A full base rotor (11) sits beneath the barrel (1) andcomprises a peripheral sidewall (12) and a lateral top wall (13) and acentral tubular axial wall (14) dimensioned to be pushed partly throughthe axial circular wall (9) of the barrel base. Tubular wall (14) has alower section forming an aperture plugged by plug (15) and from itsupper section an axial threaded spindle (16) extends into the body ofthe barrel (1). Apertures in the mounting of the spindle (16) in thetubular wall (14) permit flow therethrough of stick material when it isin fluid form. The tubular wall (14) comprises two external surfacessubstantially orthogonal to each other (17, 18) that are opposed to theinward face of walls (9) and (10) respectively. Between the opposedfaces of wall (9) and surface (17) extends a claw seal (19) and betweenwall (10) and surface (18) extends a wiper seal (20). A platform (21) islocated within barrel (1) between its base wall (8) and its open end (3)having a domed top (22), a plurality of apertures (24) and a centralthreaded bore (23) dimensioned to engage with the threaded spindle (16).

The dispenser is made by push fitting the central wall (14) of the rotor(11) through the circular section (9) of the base and the seals (19) and(20) span respectively the spaces between surfaces (9, 17) and (10, 18).The platform (21) is fitted through open end (3) and the rotor (11)rotated to wind the platform down until it encounters the barrel base.The former (3) is push fitted and the dispenser is inverted. The barrel(1) is filled with stick material (not illustrated) through theapertures in the circular wall (14) and apertures (24) in the platform(21). When the stick material has solidified, the dispenser is turnedupright and the cap fitted.

Said primary reference dispenser after 21 days had gained under the highhumid test conditions specified hereinabove on average 0.0707 g, thestarting weight of the dispenser and stick material being 85.633 g onaverage. The average weight gain per day was thus 0.003367 g.

The above-summarised formulation containing the ingredient susceptibleto photo-destruction, namely palmatine, was stored in the sameconditions in the same humidity controlled enclosures having translucentwalls at the same time and exposed to daylight in a laboratory. Thedispensers were removed from the enclosures periodically and visuallyassessed, cap and former being replaced quickly after each observation.The visual change of the stick composition in the reference, acceptable,dispenser was compared with that observed in a dispenser that had aweight gain of 0.1846 g after 21 days, i.e. a weight gain of 261% of thegain in the reference\dispenser.

In order to represent conditions during conventional use of a stick, theformer was removed before the start of the trials.

At the commencement of the trials, the stick material was the same palebeige white in appearance. After 8 days storage, the stick compositionin the reference dispenser was still pale beige white, whereas in thecomparison dispenser the composition had darkened to beige. The stickcomposition in the reference dispenser did eventually darken to beigeand observed after 16 days. This shows that the reference dispensersignificantly retarded the rate at which the ingredient susceptible tophoto-destruction was deleteriously affected and hence the referencedispenser is a suitable dispenser in accordance with the instantinvention.

1. A cosmetic product which is a composition disposed with a dispenser,in which the composition is in the form of a solid anhydrous stickcomposition containing one or more ingredients that are susceptible tophoto-destruction by visible/UV light and/or UV light and the dispensercomprises a barrel having opposed first and second ends, the first endbeing closed by a cap and the second end comprising a base, a platformintermediate between the first and second ends and screw-threaded meansfor advancing the platform towards the first end mounted on or adjacentto the second end, the composition being disposed between the platformand the first end of the barrel, in which the dispenser permits a %weight gain after 21 days in the test procedure as defined herein of notgreater than 150% of the % weight gain obtained in the referencedispenser.
 2. A cosmetic product according to claim 1 in which theingredient that is susceptible to photo-destruction by visible/UV lightis one or a mixture selected from: Molecules which produce singletoxygen under exposure to light in the range 290-740 nm, preferably up to700 nm and oxygen with a quantum yield greater than 0.05 in an organicsolvent; Molecules comprising aromatic heterocycles Phenols which lack atertiary butyl group that would serve to stabilise the phenol,Biological molecules: Vitamins, Co-enzymes, Enzymes and proteins andUnsaturated aliphatic olefinically unsaturated fatty carboxylic acids 3.A cosmetic product according to claim 2 in which the ingredient that issusceptible to photo-destruction by visible/UV light is selected from:—Aromatic heterocylic compounds, comprising a nitrogen hetero atom andparticularly when the hetero atom is charged, Unsaturated aliphaticolefinically unsaturated fatty carboxylic acids comprising a C—H bondalpha to the olefinic unsaturation; Phenols and polyphenols that are notsterically hindered and Vitamins.
 4. A cosmetic product according toclaim 1 in which the ingredient that is susceptible to photo-destructionby visible/UV light is one or more of palmatine, a C18 olefinicallyunsaturated carboxylic acid and a vitamin.
 5. A cosmetic productaccording to claim 4 in which the ingredient that is susceptible tophoto-destruction by visible/UV light is palmatine.
 6. A cosmeticproduct according to claim 1 in which the ingredient that is susceptibleto photo-destruction by visible/UV light is a dye.
 7. A cosmetic productaccording to claim 1 in which the ingredient that is susceptible tophoto-destruction by visible/UV light has a peak extinction coefficientin the visible/UV light spectrum of at least 100 mol⁻¹cm⁻¹.
 8. Acosmetic product according to claim 7 in which the ingredient that issusceptible to photo-destruction by visible/UV light has a peakextinction coefficient in the visible/UV light spectrum of at least 500mol⁻¹cm⁻¹.
 9. A cosmetic product according to claim 7 in which theingredient that is susceptible to photo-destruction by visible/UV lighthas a peak extinction coefficient in the visible/UV light spectrum of atleast 1000 mol⁻¹cm⁻¹.
 10. A cosmetic product according to claim 1 inwhich the ingredient that is susceptible to photo-destruction byvisible/UV light is present at a concentration of at least 0.0001% byweight, and preferably at least 0.001% by weight of the stickcomposition.
 11. A composition according to claim 10 in which theingredient that is susceptible to photo-destruction by visible/UV lighthas a peak extinction coefficient in the visible/UV light spectrum of atleast 500 mol⁻¹cm⁻¹.
 12. A cosmetic product according to claim 1 inwhich the stick composition comprises an astringent antiperspirant salt.13. A cosmetic product according to claim 12 in which the astringentsalt is an aluminium and/or zirconium chlorohydrate, optionallycomplexed.
 14. A cosmetic product according to claim 13 in which theastringent salt is an aluminium chlorohydrate.
 15. A cosmetic productaccording to claim 13 in which the astringent salt is an aluminiumzirconium chlorohydrate complexed with glycine.
 16. A cosmetic productaccording to claim 1 in which the dispenser permits a % weight gainafter 21 days in the test procedure as defined herein of not greaterthan 110% of the % weight gain obtained in the reference dispenser. 17.A cosmetic product according to claim 16 in which the dispenser containsan aluminium and/or zirconium chlorohydrate, optionally complexed, andthe ingredient that is susceptible to photo-destruction by visible/UVlight has a peak extinction coefficient in the visible/UV light spectrumof at least 500 mol⁻¹cm⁻¹ and is present at a concentration of at least0.0001% by weight of the stick composition.
 18. A cosmetic productaccording to claim 16 in which the ingredient that is susceptible tophoto-destruction by visible/UV light is palmatine.
 19. A cosmeticproduct according to claim 1 in which the base of the dispenser definesa central aperture through which extends a rotatable mounting for arotor on which is mounted a spindle to engage the platform, the mountingand base being spaced apart and bridged by two seals.
 20. A cosmeticproduct according to claim 19 in which the mounting and base compriseopposed axially extending concentric walls that are bridged by one sealof the two seals that is an unbroken radial annular seal.
 21. A cosmeticproduct according to claim 19 in which the mounting and the basecomprises a radially-extending wall section, which wall sections areopposed, the wall section of the mounting being located axially belowthe wall section of the base, the wall sections being bridged by anunbroken axial seal.
 22. A cosmetic product according to claim 19 inwhich the mounting and the base each comprises a radial wall sectionorthogonal to an axially extending wall, the respective radial wallsbeing opposed, the mounting radial wall being located below the baseradial wall and the respective axially extending walls being opposed andconcentric, the mounting wall being located within the base axiallyextending wall, and an annular radial seal bridging the axiallyextending walls and an axial seal bridging the radial wall sections. 23.A cosmetic product according to claim 1 in which at least one of theseals is a claw seal.
 24. A cosmetic product according to claim 1 inwhich the platform comprises at least one channel through which stickmaterial can be charged into the dispenser between the platform and thefirst end.